[Mfaizan]

Hi all,

I am facing problems in convergence for a steady state flow on CFX. I am simulating a supersonic flow using deLaval nozzle. I have three domains. 1. Surrounding air Fluid Domain. 2. Solid Nozzle domain and 3. High pressure Nitrogen Fluid Domain. I built the mesh on ICEM in an assembled form then I exported all three domains separately. I imported three domains in CFX and used GGI interface for wall connection for all three domains. It is surprising that CFX Solver changed the mesh quality which I built in ICEM. The ortho, aspect ratio and exp.factor values were changed by solver.

The simulation is failing when at a point when high pressure nitrogen mixes with surrounding air. I am posting a pictures of existing mesh. Please suggest how can I overcome this mesh problem. I don't want to increase the mesh elements. I need guidance to increase the mesh quality for supersonic flow to achieve convergence.

Any help/suggestion would be appreciated.

thanks in advance,

regards,

Faizan

[Mfaizan]

More pics attached

[Mfaizan]

more pics of mesh

[Dr. Flow Squad]

The mesh jumps to brute from one to the another.

[Mfaizan]

Hi Dr.Flow,

Yes- I agree with you. I am new to ICEM meshing. I used Bigeometric rule with 1.2 edge ratio. Now I would appreciate if you can assist me to develop a quality mesh for three domains without increasing mesh density. Any coarse mesh with high quality would be sufficient for my project because I need to expedite the convergence.

Thanks

Faizan.

[Mfaizan]

Hi all,

Please advice/suggest me as what should I do to incerase the quality of mesh on icem. I am new to ICEM and do not know much option. I am using bigeomteric rule under edge parameter. I linked the spacing with 1.2. I once increased the no. of nodes but it only increased the solver time. No significant change.

As I mentioned earlier that when I import the mesh in cfx using workbench. I used GGI interface option and cfx automatically oriented the nodes for two fluid domains and once solid domains. It is changing the mesh ortho, aspet ration but not the exp factor.

I was on other forum and a gyu told me to go to icem forum to fix the expansion ratio issue.

Please help...any expert opinion will be highly appreciated.

Thanks

[Mfaizan]

how to handle the expansion ration on ICEM???